﻿// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

 Shader "Custom/HSVShader" {     
     Properties {
              _MainTex ("Texture", 2D) = "white" {}
              _HueShift("HueShift", Float ) = 0
              _Sat("Saturation", Float) = 1
              _Val("Value", Float) = 1
              _Alpha ("Alpha", Range(0,1)) = 1     
     }
 
     SubShader {
         Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType" = "Transparent" }     
         ZWrite Off     
         Blend SrcAlpha OneMinusSrcAlpha     
         Cull Off     
       
         Pass     
         {     
             CGPROGRAM
                  
             #pragma vertex vert     
             #pragma fragment frag     
             #pragma target 2.0
             #include "UnityCG.cginc"
 
             float _Alpha;
 
             float3 shift_col(float3 RGB, float3 shift)     
             {
 
             float3 RESULT = float3(RGB);     
                float VSU = shift.z*shift.y*cos(shift.x*3.14159265/180);     
                float VSW = shift.z*shift.y*sin(shift.x*3.14159265/180);         
                RESULT.x = (.299*shift.z+.701*VSU+.168*VSW)*RGB.x     
                    + (.587*shift.z-.587*VSU+.330*VSW)*RGB.y     
                    + (.114*shift.z-.114*VSU-.497*VSW)*RGB.z;     
                
                RESULT.y = (.299*shift.z-.299*VSU-.328*VSW)*RGB.x     
                    + (.587*shift.z+.413*VSU+.035*VSW)*RGB.y
                    + (.114*shift.z-.114*VSU+.292*VSW)*RGB.z;
                
                
                
                RESULT.z = (.299*shift.z-.3*VSU+1.25*VSW)*RGB.x     
                    + (.587*shift.z-.588*VSU-1.05*VSW)*RGB.y     
                    + (.114*shift.z+.886*VSU-.203*VSW)*RGB.z;     
                
                return (RESULT);
             }
 
  
 
             struct v2f {     
                 float4  pos : SV_POSITION;     
                 float2  uv : TEXCOORD0;     
             };
 
             float4 _MainTex_ST;     
  
             v2f vert (appdata_base v)     
             {
                 v2f o;     
                 o.pos = UnityObjectToClipPos (v.vertex);     
                 o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
                      
                 return o;     
             }
 
             sampler2D _MainTex;     
             float _HueShift;     
             float _Sat;     
             float _Val;
      
             half4 frag(v2f i) : COLOR
             {
                 half4 col = tex2D(_MainTex, i.uv);     
                 float3 shift = float3(_HueShift, _Sat, _Val);     
                 
                 return half4( half3(shift_col(col, shift)), col.a * _Alpha);
             }
 
             ENDCG
 
         } 
     }
 
     Fallback "Particles/Alpha Blended"
 }